Molecular mechanisms of action are studied in parotid gland acinar cells to determine regulatory events associated with protein exocytosis. In addition to standard biochemical, immunological and morphological methods recently developed experimental techniques such as photoaffinitylabelling (8-azido cyclic [32P]-AMP), enzyme linked immunosorbent antibody technique (ELISA) and microscopic examination of subcellular fractions at the LM and EM level are part of the experimental design. Cellular responses to receptor interactions of parotid cells with B-agonists have been studied using measurements of cyclic AMP-dependent protein phosphorylation as an index. The activity is both extra-nuclear as well as associated with chromatin-bound nonhistone nuclear proteins. Redistribution of protein kinase isozymes occurs after stimulation with isoproterenol. Additional cyclic AMP-binding proteins (cAMP.PK regulatory subunits have been identified in human and rat saliva. Transcribable (poly A) mRNA has been isolated from rat parotid tissue for determining stimulation-induced gene regulation of secretory protein synthesis using specific antibody to alpha-amylase as the immunological reagent.